Some kind of Oysterling...?

Taking my starting point for this one as Crepidotus sp.

There are four Crepidotus species in Roger Phillips' Mushrooms and six in Michael Jordan's Fungi, giving a list of possible suspects that looks something like this:

The Flat Oysterling (Crepidotus applanatus)
Crepidotus epibryus
Crepidotus lundellii
Yellowing Oysterling (Crepidotus luteolus)
Peeling Oysterling (Crepidotus mollis)
Crepidotus versutus
Variable Oysterling (Crepidotus variabilis)

They're all small, white (or whitish) and most of them grow on decaying wood, twigs or other plant debris. So there go all the ID features I was hoping were gonna get me somewhere.

It doesn't look like C. mollis, because there's no obvious margin. And I don't think it's C. epibryus because that one's really small. 

Of all the Crepidotus species in Fungi, Crepidotus variabilis is the only one described as being "common". So if I had to take a punt, I'd be tempted to go with that. But then Mushrooms says, "In the past thought to be common, but many records have now been redetermined as C. cesattii." So now that doesn't seem like such a safe bet... but - what the?!? - C. cesattii isn't in either of the books. So, er, not sure where that leaves me.

Crepidotus sp.?

What I have learnt today: Should have kept a bit to get a spore print. Finding out if it's "clay pink" or "walnut brown" might have got me a bit further.